This invention relates to the field of power connections for three phase electrical motors. Such electrical motors typically have six sets of field windings which are partially interconnected to define either a delta configuration or a star configuration. However, star configurations are much more common. In either case nine terminal wires extend from the motor for completion of the interconnection of the field windings. The configuration of the external connection depends upon the applied voltage. If the motor is to be powered from a 220 volt source, connections are made so as to place the six sets of field windings into three sets of parallel pairs. For a 440 volt power supply the interconnections are made to arrange the field windings into three sets of series pairs.
Heretofore the connection of a three phase electrical motor to its power supply has been carried out by hand wiring on a custom basis. This process is labor intensive and prone to error. One solution to this problem is taught in Lamb et al. U.S. Pat. No. 4,429,935. The Lamb invention provides a multi-position electrical connector. The connector includes a socket having rows of parallel receptacles and a base having rows of upstanding blades. 220 volt power and 440 volt power are supplied to the socket, and appropriate connection to the motor is made automatically depending upon the position of the base relative to the socket. The arrangement affords a quick power change and appears to have utility in applications where such power changes are frequently required and space is not limited. However, the arrangement is complicated, large and expensive. There is a need for a simple, compact and inexpensive connector for the broad range of three phase electrical motors which are normally set to receive power at a specific voltage and which require infrequent changing thereafter.